Segmented Lid Package Structure for CTE Mismatch Control
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Solution Overview
Problem
Existing package structures for semiconductor dies face challenges due to mismatched coefficients of thermal expansion (CTE) among different elements, leading to issues such as underfill delamination and warpage.
Innovation Solution
A package structure is designed with a lid structure that covers the integrated circuit dies and exposes the underfill between them, utilizing separate sections to manage thermal expansion mismatch and protect electronic components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a lid structure is used to cover integrated circuit dies, then protection of electronic components is improved, but mismatched coefficients of thermal expansion cause underfill delamination and warpage
Solution Approach 1:
The lid structure is divided into multiple separate sections rather than a single continuous piece. This segmentation allows each section to independently accommodate thermal expansion and contraction, reducing stress on the underfill and preventing delamination while maintaining component protection
Solution Approach 2:
Different regions of the lid structure are designed with different properties - some areas have gaps or openings while others provide full coverage. This local variation in structure allows the lid to accommodate thermal expansion in specific areas while maintaining protection in other areas, resolving the contradiction between protection and thermal stability
2Productivity
If integrated circuit dies are stacked in Package-on-Package structure, then integration density is improved, but thermal expansion mismatch increases warpage risk
Solution Approach 1:
The lid structure covering the stacked dies is segmented into multiple sections, allowing each section to independently respond to thermal expansion forces. This reduces the cumulative warpage effect that would occur with a continuous lid structure covering multiple stacked dies with different thermal expansion characteristics
Solution Approach 2:
The patent addresses warpage in the vertical dimension by creating gaps and openings in the lid structure. This dimensional approach allows the structure to accommodate vertical warpage forces while maintaining horizontal coverage for component protection
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces the risk of underfill delamination and warpage, enhancing the reliability and stability of the package structure by aligning the thermal expansion characteristics of the lid structure with the substrate and package components.
Implementation Method 1
mismatched coefficients of thermal expansion (CTE) among different elements
Data Source
AI summary
A package structure is provided. The package structure includes a first package component mounted on a substrate, a lid structure disposed on the substrate and around the first package component, and a thermal interface material vertically sandwiched between the plurality of integrated circuit dies of the first package component and the lid structure. The first package component includes a plurality of integrated circuit dies and an underfill formed between the integrated circuit dies. The lid structure covers the integrated circuit dies and exposes the underfill. A first portion and a second portion of the thermal interface material are laterally separated from each other, and a space between the first portion and the second portion is exposed from the lid structure.